B. Favier

Measurements of pp→π+d between 398 MeV and 572 MeV

Abstract The reaction pp→ π + d was studied at incident proton energies of 398, 455, 497, 530 and 572 MeV. Measurements of dσ/dΩ at 455 and 572 MeV show the presence of pion d-waves in the pion-deuteron system. Asymmetry measurements yield similar conclusions. Total cross-section measurements agree with recent fits to earlier data.

A set of efficient estimators for polarization measurements

Abstract We discuss a set of robust and efficient statistical estimators for azimuthal asymmetries in the scattering of spin 1 2 particles. These estimators are easy to use and allow a posteriori corrections. Applications to p-p and p-C scattering are considered.

Measurement of p-C analyzing power with a small angle scattering system

Abstract The p-C analyzing power for 4° ≲ θ lab ≲ 20° has been measured at incident proton energies of 399, 462, 500, 515, 530 and 576 MeV. Multiwire proportional chambers were placed directly in a polarized proton beam and the azimuthal asymmetry of the scattered protons was observed. Unscattered protons were rejected with an electronic fast decision system. Some effects of inelastic scattering on the analyzing power have also been investigated.

Proton-carbon analyzing power between 300 and 560 MeV☆

Abstract The pC analyzing power has been measured for laboratory scattering angles between 5° and 20° at 299, 380, 483 and 561 MeV proton kinetic energy. The experiment was performed at SIN using a carbon analyzer sandwiched between multiwire proportional chamber telescopes placed directly in a polarized beam. Some effects of inelasticity have been investigated.

Energy dependence of the pp→π+d differential cross section between 500 and 600 MeV

Abstract The unpolarized differential cross section for the reaction pp→π + d has been measured at SIN at seven energies between 514 and 583 MeV. Data are presented in terms of a Legendre polynomial expansion. An observed strong energy dependence of the 4th order coefficient can be understood as a threshold phenomenon in a phenomenological NΔ resonant description. No evidence was found for a 1 D 2 dibaryon resonance near 600 MeV.

p(↑)+p(↑) → π+d at 515 and 578 MeV

Abstract The polarization asymmetries A 0 y and A y 0 , and the spin correlation parameter A yy have been measured at SIN at 515 and 578 MeV using a transversally polarized proton beam and target. The results are compared with various theoretical models.

Measurement of the spin correlation parameter A00nn and the polarization A00n0 in elastic p-p scattering between 400 and 600 MeV

Abstract We have measured the spin correlation parameter A 00 nn and the polarization A 00 n 0 for p-p elastic scattering in the c.m. angular range between 30° and 90° at seven energies between 400 and 600 MeV. The experiment was performed at SIN using a polarized beam and target and a fast on-line event reconstruction method. The results are compared with phase-shift predictions.

An experimental ensemble used for the study of proton-proton scattering at SIN

Abstract An experimental program on proton-proton scattering is presently running at SIN. This article gives technical details of the instruments and equipment employed. It reviews, in particular, the SIN polarized proton beam, the large scale equipment, the LH 2 and the polarized targets, the detectors, the electronics, the on-line computer and the different basic layouts. Possibly this material could be split into separated articles. However, we find it more valuable to present here a complete picture which reflects the “state of the art”.

A Complete Experiment for p p Scattering at Medium-Energies

Abstract A set of p-p scattering measurements which allows the p-p scattering matrix to be determined directly from experiment at given energies and angles is proposed and discussed. Present day experimental techniques are taken into consideration. The scattering matrix is determined independently of phase shift analyses and can be used to check the reliability of their predictions. Estimates of the precision needed in this complete experiment and the corresponding uncertainties in the scattering amplitudes are given.

Polarization measurements in p-p elastic scattering between 398 and 572 MeV

Measurements of the analyzing power for p-p elastic scattering at 398, 455, 497, 530 and 572 MeV are reported. A system of multiwire proportional chambers placed directly in a polarized beam was used to observe the angular region 1.5° < θlab < 10°. An increase in P(θ) is observed as a function of both scattering angle and incident kinetic energy. Electromagnetic-nuclear interference is used to obtain direct information on the nuclear interaction.